i must be missing something here.
is the VRI for DX and the VRII for FX?
No.
The lenses are:
70-200/2.8 VR (not VRI) and
70-200/2.8 VR II where the "II" does not refer to the type of VR employed in the lens, but rather, it refers to the entire lens as the second version (or MkII if you like) of this lens.
They are both designed for full frame coverage. However, when the first version was released in early 2003, Nikon had no full frame digital cameras on the market, so noone really knew how it would perform on those. It was a fantastic performer on the DX cameras at the time, but later on, when the D3 was released it turned out that this lens produced slightly soft corners and some vignetting at the 200 mm end wide open on full frame images.
The second version was released in the middle of 2009. It has a completely different optical design, a more advanced VR system and it is fully optimised for full frame coverage. The only issue some people have with it is that when focused close to minimum focusing distance at the 200 mm end of the zoom range its acctual focal length is reduced to about 130 mm. This is perfectly fine for some people, yet it bothers others. But the lens is very sharp corner to corner, it has less vignetting, and some even say it has improved contrast and superior colour rendering over the first generation lens.
However, for most people the the first generation lens remains a terrific option for DX users, where the lens still performs rather brilliantly.
That is why some say that if you have DX then the earlier lens will be fine, but if you use FX then its worthwhile to spend the extra money and get the MkII.
And that's all there is to it.
By the way, the MkII version is so highly regarded and so successful (high in demand) that it is unlikely to be upgraded for some years to come. So if you want to take pictures get one that is available now.
I think the first generation was eventually phased out of production and it can only be purchased today second hand. The MkII version is of course available both new and second hand.
Try them and take your pick.
Good luck.
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Cheers,
Peter Jonas